Delphi中调用dll的两种方法

动态调用Dll：

 

在type部分定义函数类型

 

 TGetDouble = function (F:Double): Double; stdcall;

 

在调用时：

procedure TForm1.Button1Click(Sender: TObject);

var

    D: Double;

    DLLHandle: THandle;

    Func: TGetDouble;

begin

 

  DLLHandle := LoadLibrary('DLLOne.dll');

  try

  @Func := GetProcAddress(DLLHandle, 'GetDouble');

 

  if Assigned(@Func) then

  begin

    D := Func(2.2);

    Edit2.Text := FloatToStr(D);

  end;

 

  finally

  FreeLibrary(DLLHandle);

  end;

end;

 

end.

 

隐式调用:

 

library DLLOne;

 

uses

  SysUtils,

  Classes;

 

{$R *.res}

 

  function GetDoubleExt(F:Double): Double;stdcall;external 'DLLTwo.dll';

  function GetInt(I:Integer): Integer;stdcall;external 'DLLTwo.dll';

 

  function GetInteger(I:Integer): Integer;stdcall;

  begin

    Result := GetInt(I);

  end;

 

  function GetDouble(D:Double): Double;stdcall;

  begin

    Result := GetDoubleExt(D);

  end;

 

exports

  GetInteger,

  GetDouble;

 

begin

end.